More Amazon extinctions looming unless action is taken: study

(Phys.org) -- Scientists in London are predicting that for many species it may take several generations after deforestation of the Amazonian rainforests in Brazil before they become extinct.

The rainforests have been subjected to widespread deforestation over recent decades as trees have been chopped down to allow areas of farmland to expand, and to make way for roads. Among the many species threatened with extinction are the Brazilian bare-faced tamarins and white-cheeked spider monkeys.

Previous mathematical models of the effects of deforestation on biodiversity have assumed the deforestation occurs as a single event. The new research extended the model to see what happens when deforestation occurs in a number of events rather than just one, which more closely models the real situation.

Leader of the research team, Dr Robert M. Ewers from Imperial College London, said there is a time lapse between deforestation and extinctions because animals do not usually die directly, but are forced to live more densely in smaller areas. This leads to increased mortality through reduced breeding rates and more intense competition for food. Mathematician Daniel Reuman, also from Imperial College, explained that if deforestation occurs in one area and then in another area before the effects of chopping down trees in the first area are felt, there is an outstanding debt.

The team used their new model to examine data on deforestation and data on individual vertebrate species affected by loss of habitat over the period 1970-2008, and they found that 80 to 90 percent of extinctions caused by existing deforestation are yet to occur, giving the rainforest a massive extinction debt.

The team also used the model to examine a range of scenarios for the future of the rainforest over the next 40 years. These included scenarios with no change from current policies to the more optimistic scenario of a halt to deforestation by 2020. They found that for the most optimistic scenario 38 species would still be lost, but in the worst case scenario 40-50 species would become extinct in the period with an extinction debt of 100 more that would be lost later.

More than 50 percent of the Amazonian rainforest in Brazil is now protected, and the rate of deforestation is declining, and rapid and widespread extinctions predicted by earlier models have proved incorrect, with species loss occurring much more slowly than predicted. The new model now shows that the effects of the deforestation that has already occurred are yet to be fully realized. Dr Ewers said the findings could be used to target conservation efforts on areas identified by the model as being regions where the extinction debt is greatest. Efforts on these areas could prevent the extinction debt from being paid.

The paper was published in Science and shows how crucial the decisions made by the Brazilian government on deforestation and development will be. Pressure from agribusiness interests and others to relax protection and rapidly develop the region in order to ease the economic crisis are likely to be devastating. Around 40 percent of tropical rainforests are located in Brazil, and they are among the worlds most biodiverse regions.

ABSTRACTPredicting when future species extinctions will occur is necessary for directing conservation investments but has proved difficult. We developed a new method for predicting extinctions over time, accounting for the timing and magnitude of habitat loss. We applied this to the Brazilian Amazon, predicting that local extinctions of forest-dependent vertebrate species have thus far been minimal (1% of species by 2008), with more than 80% of extinctions expected to be incurred from historical habitat loss still to come. Realistic deforestation scenarios suggest that local regions will lose an average of nine vertebrate species and have a further 16 committed to extinction by 2050. There is a window of opportunity to dilute the legacy of historical deforestation by concentrating conservation efforts in areas with greatest debt.

Cultivating coca bushes, the source of cocaine, is speeding up destruction of rainforests in Colombia and threatening the region's "hotspots" of plant and animal diversity, scientists are reporting in a new study. The findings, ...

Yosemite National Park is bracing for its driest year on record, with visitor bureaus downplaying the allure of the park's most famous waterfall and instead touting the park as a destination for hiking, bicycling and photography.

A new stream-based monitoring system recently discovered high levels of methane in a Pennsylvania stream near the site of a reported Marcellus shale gas well leak, according to researchers at Penn State and the U.S. Geological ...

A team led by Washington State University researchers has found that methane emissions from local natural gas distribution systems in cities and towns throughout the U.S. have decreased in the past 20 years ...

In the first-of-its-kind study of the environmental effects of hydropeaking, that is releasing water at hydropower dams to meet peak daily electricity demand, two University of Massachusetts Amherst researchers ...

Difference between extincting a necessary forest for humans to survive, or a few human sacrifices to save the thing that keeps humans alive... hmmmmm I prefer a few humans to simply die and so does NATO

Difference between extincting a necessary forest for humans to survive, or a few human sacrifices to save the thing that keeps humans alive... hmmmmm I prefer a few humans to simply die and so does NATO

I agree with your last 2 statements MM, but the Amazon has been considered one of the earths "lungs" for a long time. As well, there are over a hundred prescription medicines derived directly from rainforest vegetation. We wouldn't go extinct without it...but life would certainly suck for alot more people if we lose it.

A lot of the current agricultural pressure on rainforests is because of biofuels. Growing biofuels takes land. The available land has forest on it. As a result of the demand for biofuels, rainforest gets cut down. The consequences of environmental policies can be very bad for the environment sometimes...

A lot of the current agricultural pressure on rainforests is because of biofuels. Growing biofuels takes land. The available land has forest on it. As a result of the demand for biofuels, rainforest gets cut down. The consequences of environmental policies can be very bad for the environment sometimes...

A boldly anti-environmental claim that simply won't stand up to scrutiny. If you bother to rein in your agenda-driven lying for just a moment, and actually bother to look for the truth of the matter, you'll find that most of this deforestation occurs as "entrepreneurs" slash-and-burn the rainforest in order to utilize the land for three or four years(before the very poor soil is exhausted) of beef production so that fat, stupid, lazy Americans can gorge themselves on poison meals at McDonalds, Burger King, and the many YUM FOODS brands, to name just a few. Logging and Mining operations account for most of the remaining deforestation.

As long as species have been evolving on earth, they have been going extinct. It is estimated that over 99.9% of all species that ever lived are now extinct. Who gives a rats a$$ if the red-haired butt headed tit monkey, becomes extinct or not,... they probably don't even taste good anyway.

The more raw natural data humans accumulate in the study of nature, the more evironmentalists and naive bed wetters generally, become emotionally reactionary to it. That "we" should do this and "we" should do that, is just irrational naive drivel.

Just because one notices what he perceives as an "ill" in nature, doesn't mean that 'the machine' is "malfunctioning", or that he can do anything about it, if it is even meaningful to say that it is "malfunctioning". How "should" it be,.. what temp "should" the global climate be,.. what species are the right ones to exist?

Man will not be able to get out of his own way and leave the earth as if his nature didn't exist.

Man's basic instinct is to kill. When only humans remain, they then will be hunted for sport and their byproducts used for biofuel.

The only use for predictions from a hysterical tree-hugger, is for sci-fi stories.

It's clear that you think that man is a parasite upon the otherwise pristine earth. This mind set along with anti-capitalism and anti-freedom, is the significant danger to mankind to be concerned about. Read history.

Man's basic instinct is to kill. When only humans remain, they then will be hunted for sport and their byproducts used for biofuel.

The only use for predictions from a hysterical tree-hugger, is for sci-fi stories.

It's clear that you think that man is a parasite upon the otherwise pristine earth. This mind set along with anti-capitalism and anti-freedom, is the significant danger to mankind to be concerned about. Read history.

Sure, mankind is no parasite, but capitalism is, in a huge way, read history.

So what, exactly, do you mean to say by that, Mm? are they queueing up in record numbers for Happy Meals in Bangladesh?

No Indeed Caliban. You are a quite intelligent human being, I think you took my point.

However, in case you didn't I'll explain. You accused Rik of having an agenda (which he has) and then proceeded to display your own in spades. I'm not saying it's wrong to have an agenda, or even possible not to have one. I'm saying that when we start to define ourselves by those we disagree with and hold on to those opinions like gold we can miss out on anything valuable they have to say. Moreover, when we communicate with our "enemies" with that state of mind we totally cut off any possibility of them learning the valuable things we have to say.

When you pound a hammer into the ground for eight hours a day for a year you've done a lot of labor, but at the end of the year what do you have other than some well pounded ground?

I'm not saying that we're not "parasitic" right now, and have been so for many many years. I'm saying that mankind is not parasitic in itself. If we rebuild society, the planet would not suffer.

Planets don't "suffer" nor do they have feelings. Humans suffer though, and what prevents human suffering is innovation and technology, which comes into use on a mass scale most efficiently, through capitalism.

The problem is in what you mean by "rebuild society". The political left want government control by social engineering and manipulation of human behavior, while the political right want freedom & capitalism.

History has shown that capitalism has been the greatest force for social progress, innovation, and increased life expectancy, in human history, while gov's are bankrupt.

.....The political left want government control by social engineering and manipulation of human behavior, while the political right want freedom & capitalism.....

Anti-capitalism implies socialism and social engineering, big gov control and involvement. Just from a practical stand point, this methodology works against the grain of human nature and so, is much less likely to be successful in the end,... while freedom, capitalism and limited gov, takes advantage of the already existent force inherent in human nature.

So what, exactly, do you mean to say by that, Mm? are they queueing up in record numbers for Happy Meals in Bangladesh?

No Indeed Caliban. You are a quite intelligent human being, I think you took my point.

However, in case you didn't I'll explain. You accused Rik of having an agenda (which he has) and then proceeded to display your own in spades. I'm not saying it's wrong to have an agenda, or even possible not to have one. I'm saying that when we start to define ourselves by those we disagree with and hold on to those opinions like gold we can miss out on anything valuable they have to say. Moreover, when we communicate with our "enemies" with that state of mind we totally cut off any possibility of them learning the valuable things we have to say.

Excellent, Mm. I recommend that you take a page from your own book, and practice what you preach, as I am certain that you -and possibly rikvanriel- also understood my point.

So drop the sanctimonious tone.

Please sign in to add a comment.
Registration is free, and takes less than a minute.
Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.